The reaction for all the enzymes was stopped by adding 0.5 ml of 10% perchloric acid per 1 ml of reaction mixture after a specific time of reaction, followed by centrifugation to precipitate out the protein. Citrulline formed in the case of CPS and OTC, citrulline used in the case of ASS, and urea formed in the case of ASL and ARG, were measured spectrophotometrically
(Beckman, DU 640) in the supernatant (Moore and Kauffman, 1970) and expressed as enzyme